Total Magnetic Losses Research Articles

Optimizing Magnetic Separation and Cleaning Module in Fully Automated Chemiluminescence Immunoassay Analyzer Using a Special Arrangement of Spliced Magnets and a Three-Stage Magnetic Bead Collection Method

The magnetic separation and cleaning module, as a core component of the fully automated chemiluminescence immunoassay (CLIA) analyzer, encounters issues including high magnetic bead loss rate, long cleaning time, and poor cleaning effect. Based on a simulation analysis using COMSOL, we proposed a novel magnetic separation and cleaning module applied to a fully automated CLIA analyzer. The module adopted a method of arranging spliced rectangular magnets on opposite sides, where the same polarity faced each other, as well as a three-stage magnetic bead collection method. With the proposed method, the total cleaning process can be accomplished within 225 s; the total magnetic bead loss rate over three rounds of cleaning is 6.03%, whereas that of traditional instruments is 25.85%; the coefficient of variation (CV) of the magnetic bead loss rate is less than 0.5%; effective cleaning of free markers is achieved under various sample conditions. Compared with traditional CLIA instruments, this method comprehensively improves key performance indicators of the magnetic separation and cleaning module, providing a reference for similar modules in fully automated CLIA analyzers and positively impacting the accuracy of CLIA for the detection of disease biomarkers.

Evolution of Crystallographic Texture and Its Impact on Magnetic Losses of Non‐oriented Electrical Steel

In this study, how crystallographic texture and changes in microstructure affect the magnetic properties of a semi‐processed non‐oriented (NO) electrical steel, which is investigated in its as‐received state and after heat treatment, is evaluated. Electron backscattered diffraction analysis shows the variation in texture with a crystallographic orientation changing from a predominance of γ and α fibers to a random one after heat treatment, with a significant increase in components with <100> directions in the sheet plane, which are desired for NO steels because they are parallel to the direction of easy magnetization. Heat treatment has also increased the average grain size of the samples from 18 to 128 μm. Magnetic properties are analyzed over a wide frequency range and induction, presenting different behaviors in permeability and magnetic loss for the samples before and after heat treatment. The components of total magnetic loss are also evaluated, and the hysteresis loss of heat‐treated sample decreases significantly. This demonstrates that heat treatment reduces microstructural imperfections, causing a decrease in hysteresis losses. Therefore, it is concluded that the improvement in magnetic performance observed with heat treatment has its origin in the increase in fiber components related to the <100> directions and a decrease in microstructural imperfections.

Effects of WEDM and AWJ cutting methods on induction motor efficiency and total magnetic losses: Experimental design and response surface methodology

In this study, the effect of cutting electrical steel laminations using abrasive water jet (AWJ) and wire electrical discharge machining (WEDM) techniques on 5.5 kW induction motor efficiency (MEfficiency) and total magnetic losses (TLosses) was investigated. After the stator and rotor packages were formed, winding, varnishing and mechanical assembly processes were carried out and the motors were prepared for MEfficiency and TLosses tests according to the IEC 60034-2-1-1A standard. Tests were performed using different frequencies (f) and motor loading rates (MLoad). While burr formation was observed with the effect of plastic deformation on the cutting edge of electrical steels with AWJ, recast layer formation was observed with the effect of heat in WEDM. MEfficiency decreased while TLosses increased due to increasing f and MLoad in both cutting methods. Maximum MEfficiency and minimum TLosses values were measured in WEDM, it was determined that optimum results using Response Surface Methodology (RSM) were measured at f of 50 Hz and MLoad of 100% values in both cutting methods. The statistical effects of f and MLoad on MEfficiency and TLosses were revealed with ANOVA (Analysis of variance). In addition, mathematical models were developed for the prediction of MEfficiency and TLosses.

ULTRASONIC METHOD FOR SURFACE TREATMENT OF ANISOTROPIC ELECTRICAL STEEL TO REDUCE ITS TOTAL MAGNETIC LOSSES FOR MAGNETIZATION REVERSAL

The paper describes an ultrasonic method for the formation of locally deformed zones (LDZ) in the form of mechanical scratches applied to the surface of anisotropic electrical steel of nuclear power plants to crush its domain structure in order to reduce the total magnetic losses Р. It is shown that, as a result of such processing, using the example of a 3407 type steel, the value of P decreases by an average of 10-15%. It has been established that exposure to ultrasound leads to a significant increase in the rate of scratching.

Ultrasonic Method of Surface Treatment of Anisotropic Electrical Steel to Reduce Its Total Magnetic Losses for Remagnetization

Ultrasonic Method of Surface Treatment of Anisotropic Electrical Steel to Reduce Its Total Magnetic Losses for Remagnetization

Analysis of the Mechanical Properties of Electrical Steel

Abstract This paper presents the microstructural aspects of strips cold rolled laminar and the influence of grain size on the total magnetic loss at 1T respectively 1.5T, for silicon steel strips with non-oriented grains after decarburized and annealed treatment. We find that the hardness at the head of the rolls is higher for all 5 analyzed rolls, on the other hand, for the rolls from batch II the hardness at the ends is higher than the hardness at the head. The hardness values are included in the EN standards 10106. The regression equations drawn for Rc in the raw state, as well as in the aged state, show us significant correlation coefficients very close to the value of 1, that is 0.98 for Rc raw and 0.97 for Rc aged.The regression equations plotted for Rm in the raw state for the batch of bands analyzed, as well as in the aged state, show us significant correlation coefficients very close to the value of 1, i.e. 0.91 for Rm raw and o.98 for Rm aged.

Experimental and statistical analysis of the effects of punching and laser cutting methods on induction motor efficiency and total magnetic losses in silicon lamination sheets

In this study, M400-50A electrical steel laminations (ESLs) used in electrical machines were cut with punching and laser methods and the effect of these cutting methods on the efficiency and total losses of induction motors was investigated. ESLs were prepared by laser and punching cutting methods concerning an induction motor with a power of 5.5 kW. After the stator and rotor packages were created, processes such as winding, varnishing, and mechanical assembly were performed on the motors. It is prepared for motor efficiency (MEfficiency) and total magnetic losses (TLosses) tests according to the direct measurement method specified in the IEC 60034-2-1-1A standard. Four different frequencies (f: 50, 75, 100 and 125 Hz) and five different motor loading rates (MLoad: 25, 50, 75, 100 and 125%) were defined as independent variables in the tests. MEfficiency and TLosses values were measured as dependent variables. Plastic deformation and edge rounding were observed on the edges cut with punching and edge rounding and angled edge formation on the edges cut with the laser. The average surface roughness of the laser-cut edges was determined to be higher than the ESLs cut by punching. It was observed that TLosses increased while MEfficiency decreased with increasing frequency and MLoad value in motor tests. It was determined that the training, testing, and experimental data are quite compatible with each other and the R2 values are close to 1 in the statistical analyzes performed with ANN (Artificial neural network). In addition, it was specified that RMSE (Root mean square error) and MAPE (Mean absolute percentage error) values vary between 0.007 and 13.310% for each cutting method and mathematical models can be used to predict MEfficiency and TLosses with ANN.

Compact Integrated Transformer – Grid Inductor Structure for E-Capless Single-Stage EV Charger

This article proposes a planar magnetic integration technique that combines the grid inductors and transformer in the single-stage E-capless electric vehicle charger into one core. The proposed integration technique reduces the number of magnetic components; therefore, the cost, total magnetic core loss, and volume can be significantly reduced. Using the integrated structure, the overall converter power density increases up to 11.1% compared to the nonintegrated one. This article also presents a detailed analysis of the optimal printed circuit board (PCB) winding arrangement considering both ac resistance and winding stray capacitance. Due to the high dc resistance of PCB winding, Litz wire was also considered for the proposed integrated structure. The effectiveness of the proposed structure was validated by implementing it on a 3.7-kW prototype of a single-stage ac–dc converter. Results show that the prototype with the proposed integrated structure achieved higher efficiency with both PCB winding and Litz wire. Peak efficiency of 97.17% and 6.55-kW/L power density were achieved.

Magnetically active coatings for electrical materials

The prospects of using nitride-oxide and magnesium phosphate electrical insulating coatings on thin strips of magnetically soft alloys based on silicon iron are considered. X-ray diffraction topography, powder figures, and magnetic measurements have shown that coatings create uniformly distributed tensile stresses in materials, increase uniaxial magnetic anisotropy, and reduce the volume of transversely magnetized domains and the width of longitudinally magnetized ones. This increases magnetic permeability and significantly decreases the coercive force, as well as eddy-current and total (by 20–25 %) magnetic losses. Tensile (magnetically active) coatings enhance the effect of subsequent thermomagnetic treatment of alloys.

Estimation of Energy Losses in Nanocrystalline FINEMET Alloys Working at High Frequency

Soft magnetic materials are at the core of electromagnetic devices. Planar transformers are essential pieces of equipment working at high frequency. Usually, their magnetic core is made of various types of ferrites or iron-based alloys. An upcoming alternative might be the replacement the ferrites with FINEMET-type alloys, of nominal composition of Fe73.5Si13.5B9Cu3Nb1 (at. %). FINEMET is a nanocrystalline material exhibiting excellent magnetic properties at high frequencies, a soft magnetic alloy that has been in the focus of interest in the last years thanks to its high saturation magnetization, high permeability, and low core loss. Here, we present and discuss the measured and modelled properties of this material. Owing to the limits of the experimental set-up, an estimate of the total magnetic losses within this magnetic material is made, for values greater than the measurement limits of the magnetic flux density and frequency, with reasonable results for potential applications of FINMET-type alloys and thin films in high frequency planar transformer cores.

Influence of the cutting process, heat treatment, and maximum magnetic induction on the magnetic properties of highly oriented electrical steels

In this work, the dynamic losses of modern high-permeability grain-oriented (HGO) electrical steel were investigated as a function of the clearance used during the shear cutting process and the frequency of the applied magnetic field from 3 up to 1000 Hz. The strips were shear cut at clearances of 0.01, 0.04, 0.05, 0.10 and 0.15 mm, and after cutting the samples were heat treated at 850 °C for 1 h. The edge regions were analysed using optical microscopy before and after the heat treatment, and a significant mechanical deformation and consequently a deterioration of magnetic properties was observed, which can be restored through stress-relief annealing. Clearances of 0.01, 0.04, 0.05 and 0.10 mm exhibit the same total magnetic loss; however, for the clearance of 0.15 mm, it increases by ≈10% due to the crack in the fracture zone and greater rollover region. The heat treatment improves the magnetic performance of the as-cut HGO steel strips by ≈8% and ≈15% for 1.5 and 1.7 T, respectively, at frequency of 60 Hz. Finally, a detailed study of the dependence of the losses (hysteresis Ph, classical eddy current Pc, and excess Pe) on frequency and maximum induction was performed. Interestingly, it was observed that Ph is much more influenced by clearance than other losses. In addition, the role of the maximum induction Bmax on each loss component was investigated as a function of frequency. Our findings show that below 0.2 T Pc is larger than Pe and Ph, however, above this threshold there is an inversion where Pe is larger than the other two components in the entire frequency range, even with 1.5 T of magnetic induction. This can indicate that different physical mechanisms that constitute the permeability spectrum exhibit different relaxation times, therefore, they are activated at different frequencies and magnetic field intensities.

Microstructure and magnetic properties of FeSiAl soft magnetic composites prepared by chemical in-situ coprecipitation with NaOH

The FeSiAl powder was dispersed into NaOH solution with 10 wt% concentration, after a certain time then NaHCO3 with 2 wt% concentration was added. After calcination at 1250 °C, the coating changed into the oxide insulation on the surface of FeSiAl particles. The microstructure, formation mechanism, and magnetic properties of the coated powder prepared by the chemistry in-situ generation method has been investigated. The electrical insulation layer oxide was confirmed that there existence of Al2O3 phase. The thickenss of coating layer was about 20 nm measured by the TEM. The saturation magnetization (Ms) of FeSiAl powder slightly increased after coated, but obviously increased after calcined. Then the FeSiAl resistivity obviously increased after coated, and further increased after calcination. The FeSiAl soft magnetic composite has the magnetic properties of effective permeability μe = 56.03 and total magnetic loss Pcv = 1042.86 mW/cm3 that measured under the condition of frequency 1000 kHz and 20 mT. This is an effective method to prepare high performance FeSiAl@Al2O3 soft magnetic composite applied at higher frequency.

Effect of dipolar interactions on cavity magnon polaritons

The strong photon-magnon coupling between an electromagnetic cavity and two yttrium iron garnet (YIG) spheres has been investigated in the context of a strong mutual dipolar interaction between the spheres. A decrease in the coupling strength between the YIG spheres and the electromagnetic cavity is observed, along with an increase of the total magnetic losses, as the distance between the spheres is decreased. A model of inhomogeneous broadening of the ferromagnetic resonance linewidth, partly mitigated by the dipolar narrowing effect, reproduces the reduction in the coupling strength observed experimentally. These findings have important implications for the understanding of strongly coupled photon-magnon system involving densely packed magnetic objects, such as ferromagnetic nanowires arrays, in which the total coupling strength with an electromagnetic cavity might become limited due to mutual dipolar interactions.

The impact of bending stress on magnetic properties of Finemet type microwires and ribbons

In our research we studied the influence of bending on the total magnetic losses, the coercivity of minor hysteresis loops and the virgin magnetization curves of amorphous ribbons and microwires prepared from Finemet-type alloy wound on a mandrel of different diameters. The impact of various factors contributing on static and dynamic magnetic properties through bending stress are discussed. The factors pertain to contribution of the magnetoelastic anisotropy, the onset of the strain-induced magnetization, the changes of domain structure and the mobility of domain walls. The major contribution of hysteresis losses as-compared to the eddy-current losses have been observed on changing the mandrel diameter in wound ribbons and wires. The total specific losses of the Finemet-type ribbons are lower than that of microwires at the frequencies ranging from 50 to 400 Hz. Observed difference in the magnetic properties is attributed to different magnetization processes of amorphous microwires and ribbons. A different geometry and magnetoelastic anisotropy of studied materials are most likely to influence the formation of different domain structures.

Specific Features of the Frequency Variations in Magnetic Losses in Fe–3%Si {110} Crystals in Rotating Magnetic Fields

The frequency dependence of the total and eddy-current magnetic losses Ptot and Pedd for rotary magnetization reversal has been studied on an Fe–3%Si single crystal with a thickness of d = 0.10 mm within a range of frequencies f = 20–200 Hz and induction amplitudes Bm = 0.25–1.90 T. Some new specific features in the behavior of magnetic losses have been revealed. In particular, the induction that corresponds to the maximal magnetic losses in the curve Ptot = P(Bm) has been established to monotonically decrease with increasing frequency of magnetic field rotation. The specific features of the frequency variation of magnetic losses were discussed based on the observed dynamics for the domain structure of the specimen.

Оптимизация деформационными воздействиями структуры и свойств Fe-Si сплавов с разной текстурой

The influence of the degree of perfection rib crystallographic texture (110)[001] on the effect of reducing the magnetic losses at the local laser treatment and mechanical scribing process of tapes mono-crystals and poly-crystals ribbons of electrical-technical steel Fe-3% Si in condition thermo-magnetic treatment (TMT) and stretching have been studied. The samples in the form of single crystals with dimensions of 120x10x0.2 mm were studied. Their surface (110) was at angles =0-6° with the [001] axis and the magnetization vector. Sam-ples of polycrystalline textured steel were used in the form of the most common grades 3409 and 3407. The most used brands 3409, 3407 were used for samples in the form of polycrystalline textured steel tape. Their thickness was 0.27 mm, and the grain size was 20-30 mm. As a result of these effects, a narrow-domain structure of general strip 180° domains 0.2-0.3 mm in width is formed in steel, change of the type and density of the 180° and 90° domain structures, which leads to a decrease in the velocities of the motion of domain walls, and, consequently, hysteresis and eddy current magnetic losses. A sharp dependence of the effect of decreasing magnetic loss-es on the degree of perfection of the crystallographic texture was revealed. It is shown that in the case of the different steel texture of (grade 3409, 3407) after these treatments decrease in total magnetic losses of 18 and 13%, respectively, and for single crystals with optimum texture when scribing and tension - up to 32–37%.

Study on Influence of Microstructure and Thermal Treatment on Magnetic Losses from Non-Oriented Silicon Electrical Steel

Abstract Non/oriented electrical sheets are sheets tailored to produce specific properties and are produced from Fe-Si or Fe-Si-Al alloys. Non-oriented electrical steel sheets are incorporated into a wide range of equipment, from the simplest domestic appliances to hybrid and pure electric vehicles. In studying about the magnetic, there have a lot of method can be used for the different experiment requirement such as measuring magnetic flux, nominal loss and other objectives. During electrical steel processing, there are usually small variations in both chemical composition and thickness in the hot-rolled material that may lead to different magnetic properties for the same steel grade. Therefore, it is of great importance to know the effects of such variations on the final microstructure and magnetic properties of these steels. The purpose of this work was to study microstructural changes of the bands investigated during processing occurring siliceous strips with non-oriented grains. The second aim was to study the influence of grain size on the total magnetic losses at 1.0 T and 1.5 T. Materials 10 rolls intended to be processed into quality electrical steel M400-50A (according to EN 100027-1) were analyzed with metallographic microscope Neophet 32 and the magnetic characteristics was made with Epstein frame according IEC 6040/4-2, with an exiting current frequency of 50Hz at 1.5T and 1.0T induction after aging treatment of 225°C for 24 hours. Sample for light microscopy observation were prepared by polishing and etching in 5% Nital.

Assessment of the Structure and Core Losses Pertaining to Magnetic Toroids Made from Powder and Cast in One Production Step

This paper presents the results of a comparison of two methods for the preparation of permalloy-type material. The nominal blend composition was Ni80-Fe14.7-Mo4.5-Mn0.5-Si0.3. Samples were prepared in the form of toroids using powder metallurgy and an induction casting method. The following measurements were carried out on samples: computer tomography, VSM, XRD, and measurement of the total magnetic losses at different frequencies and the magnetic induction. Both technologies were found to create a crystalline material with similar phases. The sample prepared by the induction casting method exhibited high coercivity, low magnetization saturation and high excess losses in comparison with the sample that had been subjected to a 24h and 120h milling duration.

Magnetic Properties of Electrical Steel Sheets in Respect of Cutting: Micromagnetic Analysis and Macromagnetic Modeling

This paper provides a quantitative analysis of the degradation of the magnetic properties of nonoriented electrical steel sheets caused by laser, guillotine, and spark erosion cutting as well as the healing effect of stress relief annealing. For this purpose, the macroscopic material characteristics, such as commutation curves, dynamic hysteresis loops, and magnetic power losses, are gained by single-sheet tester measurements. The experiments are conducted on specimens composed of strips of variable width to adjust different degrees of total degradation. The origin of the observed changes of the material is elucidated by micromagnetic measurements based on the magneto-optical Kerr effect that visualizes the domain patterns and wall movements near the cutting edges. A local magnetic contrast is defined, which serves as a quantitative measure for the local degree of deterioration. The use of homogenous parameters within a numerical loss model based on the principle of loss separation is theoretically justified and experimentally proved to provide correct values of the total magnetic power loss for arbitrary magnetizations in degraded steel sheets.

Iron losses during desulphurisation of hot metal utilising co-injection of Mg and CaC2 combined with nepheline syenite

Iron losses during hot metal desulphurisation using magnesium and calcium carbide have been studied by large scale investigations of slag from the slag pit as well as slag sampling during desulphurisation at SSAB EMEA in Luleå. The desulphurisation slag after co-injection is normally solid and contains a large amount of iron. An alkali containing mineral, nepheline syenite, was mixed with calcium carbide to enhance the separation of iron from the slag. Even though the addition of nepheline syenite resulted in a more fine grained slag, no reduction of the iron content in the slag was observed before slag skimming. Nepheline syenite has a positive effect on slag skimming; however, the total magnetic iron losses have not decreased significantly. The increased turbulence during injection of magnesium could explain the lack of improved iron yield. The addition of nepheline syenite does not have a negative influence on the reagent efficiency.